Start Channel (MQTT)
The Start Channel (MQCMD_START_CHANNEL) command starts an IBM MQ channel. This command can be issued to a channel of type MQCHT_MQTT.
Required parameters
- ChannelName (MQCFST)
- Channel name (parameter identifier: MQCACH_CHANNEL_NAME).
The name of the channel to be started. The maximum length of the string is MQ_CHANNEL_NAME_LENGTH.
This parameter is required for all channel types including MQTT channels.
- ChannelType (MQCFIN)
- The type of channel (parameter identifier: MQIACH_CHANNEL_TYPE). This parameter is currently only used with MQTT Telemetry channels, and is required when starting a Telemetry channel. The only value that can currently be given to the parameter is MQCHT_MQTT.
Error codes
This command might return the following error codes in the response format header, in addition to the values shown in Error codes applicable to all commands.
- Reason (MQLONG)
- The value can be any of the following values:
- MQRCCF_PARM_SYNTAX_ERROR
- The parameter specified contained a syntax error.
- MQRCCF_PARM_MISSING
- Parameters are missing.
- MQRCCF_CHANNEL_NOT_FOUND
- The channel specified does not exist.
- MQRCCF_CHANNEL_IN_USE
- The command did not specify a parameter or parameter value that was required.
- MQRCCF_NO_STORAGE
- Insufficient storage is available.
- MQRCCF_COMMAND_FAILED
- The command has failed.
- MQRCCF_PORT_IN_USE
- The port is in use.
- MQRCCF_BIND_FAILED
- The bind to a remote system during session negotiation has failed.
- MQRCCF_SOCKET_ERROR
- Socket error has occurred.
- MQRCCF_HOST_NOT_AVAILABLE
- An attempt to allocate a conversation to a remote system was unsuccessful. The error might be transitory, and the allocate might succeed later. This reason can occur if the listening program at the remote system is not running.
Parent topic: Definitions of the Programmable Command Formats